T-Invariance Check in 635 MeV Elastic Proton-Proton Scattering

Abstract

Interaction invariance with respect to time-inversal results in the well-known “polarization asymmetry” equality (P= a) for nucleon-nucleon elastic scattering /1,2/. The experimental check of this conclusion performed earlier at 142–210 MeV /3–5/ is also important even at higher energies both due to the fundamental principles on which the equality under study is based and the feasible dependence of T-invariance violation upon energy. For this purpose the polarization P(o) was measured in the angle region from 34° to 117°c.m.s. The results were compared with the appropriate values of a(o) obtained in ref. /6/. The polarization P(o) was determined in the triple proton scattering on parallel planes when the first scattering occurred inside the accelerator vacuum chamber. The obtained proton beam having the polarization as large as 0.425±0.013 /7/ was scattered for a second time on a hydrogeneous (CH2-C) target at an angle O2. The polarization was analytAd by proton scattering on carbon at an angle of O3 = 8°±1°30’. In the case when the planes of all scatterings coincided, the left-right asymmetries e+ and e- which are observed in the analysing scattering and correspond to reciprocally opposite normal directions to the second scattering plane make is possible to find polarization by the known formular /1,3/ P(O) = 1/2P3 {e+(1+a P1)-e-(1-a P1)} Here P3 is the analysing power in the third scattering; P1 is the beam polarization after the first scattering; a is asymmetry arising in scattering of the totally polarized proton beam on hydrogen.